1. Field of the Invention
The invention relates to a coupling device for coupling a wheel to a golf trolley, more particularly to a coupling device which facilitates assembly and disassembly of a wheel to and from a wheel strut of a golf trolley.
2. Description of the Related Art
Referring to FIG. 1, a conventional golf trolley is shown to comprise an elongated chassis member 11, a seating 12 mounted on a lower end of the chassis member 11 and used to support a lower end of a golf bag (not shown) thereon, and a handle member 14 with a top end formed with a grip portion 15 and a lower end connected to an upper end of the chassis member 11 by means of a handle mounting bracket 13. A connecting plate 16 is secured to an intermediate portion of the chassis member 11. The golf trolley further comprises two wheel strut units 170, each of which having a first end secured to the connecting plate 16 and an opposite second end secured to a wheel mounting bracket 17. Each of a pair of wheels 18 has a rotatable axle 19 mounted on a respective one of the wheel mounting brackets 17.
FIG. 2 illustrates how the wheel 18 is mounted rotatably on the respective wheel mounting bracket 17. A connecting tube 172 is welded on a rear surface of the wheel mounting bracket 17. A nut 173 is welded on an outer surface of the connecting tube 172 and confines a threaded hole 174 which is communicated with the interior 175 of the connecting tube 172. The axle 19 of the wheel 18 is formed with a radial through-hole 191.
During assembly, the axle 19 extends into the interior 175 of the connecting tube 172 such that the radial through-hole 191 is aligned with the threaded hole 174 of the nut 173. The threaded shank 178 of a rotary knob 176 engages threadedly the nut 173 and extends into the radial through-hole 191, thereby securing the wheel 18 onto the wheel mounting bracket 17. In order to minimize undesired rotation of the rotary knob 176 after assembly, a spring 177 is provided between the head portion 179 of the rotary knob 176 and the outer surface of the connecting tube 172.
It is noted that the wheel mounting bracket 17 is inconvenient to manufacture because of the need to weld the connecting tube 172 and the nut 173 thereon. Furthermore, it is difficult to align the radial through-hole 191 of the axle 19 with the threaded hole 174 of the nut 173 during assembly. In addition, the spring 177 is easily misplaced when the wheel 18 is detached from the wheel mounting bracket 17.